File: dgsvts.f

package info (click to toggle)
lapack 3.0.20000531a-18
  • links: PTS
  • area: main
  • in suites: woody
  • size: 59,896 kB
  • ctags: 45,291
  • sloc: fortran: 571,183; perl: 8,226; makefile: 2,328; awk: 71; sh: 45
file content (279 lines) | stat: -rw-r--r-- 8,790 bytes parent folder | download | duplicates (6)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
      SUBROUTINE DGSVTS( M, P, N, A, AF, LDA, B, BF, LDB, U, LDU, V,
     $                   LDV, Q, LDQ, ALPHA, BETA, R, LDR, IWORK, WORK,
     $                   LWORK, RWORK, RESULT )
*
*  -- LAPACK test routine (version 3.0) --
*     Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
*     Courant Institute, Argonne National Lab, and Rice University
*     June 30, 1999
*
*     .. Scalar Arguments ..
      INTEGER            LDA, LDB, LDQ, LDR, LDU, LDV, LWORK, M, N, P
*     ..
*     .. Array Arguments ..
      INTEGER            IWORK( * )
      DOUBLE PRECISION   A( LDA, * ), AF( LDA, * ), ALPHA( * ),
     $                   B( LDB, * ), BETA( * ), BF( LDB, * ),
     $                   Q( LDQ, * ), R( LDR, * ), RESULT( 6 ),
     $                   RWORK( * ), U( LDU, * ), V( LDV, * ),
     $                   WORK( LWORK )
*     ..
*
*  Purpose
*  =======
*
*  DGSVTS tests DGGSVD, which computes the GSVD of an M-by-N matrix A
*  and a P-by-N matrix B:
*               U'*A*Q = D1*R and V'*B*Q = D2*R.
*
*  Arguments
*  =========
*
*  M       (input) INTEGER
*          The number of rows of the matrix A.  M >= 0.
*
*  P       (input) INTEGER
*          The number of rows of the matrix B.  P >= 0.
*
*  N       (input) INTEGER
*          The number of columns of the matrices A and B.  N >= 0.
*
*  A       (input) DOUBLE PRECISION array, dimension (LDA,M)
*          The M-by-N matrix A.
*
*  AF      (output) DOUBLE PRECISION array, dimension (LDA,N)
*          Details of the GSVD of A and B, as returned by DGGSVD,
*          see DGGSVD for further details.
*
*  LDA     (input) INTEGER
*          The leading dimension of the arrays A and AF.
*          LDA >= max( 1,M ).
*
*  B       (input) DOUBLE PRECISION array, dimension (LDB,P)
*          On entry, the P-by-N matrix B.
*
*  BF      (output) DOUBLE PRECISION array, dimension (LDB,N)
*          Details of the GSVD of A and B, as returned by DGGSVD,
*          see DGGSVD for further details.
*
*  LDB     (input) INTEGER
*          The leading dimension of the arrays B and BF.
*          LDB >= max(1,P).
*
*  U       (output) DOUBLE PRECISION array, dimension(LDU,M)
*          The M by M orthogonal matrix U.
*
*  LDU     (input) INTEGER
*          The leading dimension of the array U. LDU >= max(1,M).
*
*  V       (output) DOUBLE PRECISION array, dimension(LDV,M)
*          The P by P orthogonal matrix V.
*
*  LDV     (input) INTEGER
*          The leading dimension of the array V. LDV >= max(1,P).
*
*  Q       (output) DOUBLE PRECISION array, dimension(LDQ,N)
*          The N by N orthogonal matrix Q.
*
*  LDQ     (input) INTEGER
*          The leading dimension of the array Q. LDQ >= max(1,N).
*
*  ALPHA   (output) DOUBLE PRECISION array, dimension (N)
*  BETA    (output) DOUBLE PRECISION array, dimension (N)
*          The generalized singular value pairs of A and B, the
*          ``diagonal'' matrices D1 and D2 are constructed from
*          ALPHA and BETA, see subroutine DGGSVD for details.
*
*  R       (output) DOUBLE PRECISION array, dimension(LDQ,N)
*          The upper triangular matrix R.
*
*  LDR     (input) INTEGER
*          The leading dimension of the array R. LDR >= max(1,N).
*
*  IWORK   (workspace) INTEGER array, dimension (N)
*
*  WORK    (workspace) DOUBLE PRECISION array, dimension (LWORK)
*
*  LWORK   (input) INTEGER
*          The dimension of the array WORK,
*          LWORK >= max(M,P,N)*max(M,P,N).
*
*  RWORK   (workspace) DOUBLE PRECISION array, dimension (max(M,P,N))
*
*  RESULT  (output) DOUBLE PRECISION array, dimension (6)
*          The test ratios:
*          RESULT(1) = norm( U'*A*Q - D1*R ) / ( MAX(M,N)*norm(A)*ULP)
*          RESULT(2) = norm( V'*B*Q - D2*R ) / ( MAX(P,N)*norm(B)*ULP)
*          RESULT(3) = norm( I - U'*U ) / ( M*ULP )
*          RESULT(4) = norm( I - V'*V ) / ( P*ULP )
*          RESULT(5) = norm( I - Q'*Q ) / ( N*ULP )
*          RESULT(6) = 0        if ALPHA is in decreasing order;
*                    = ULPINV   otherwise.
*
*  =====================================================================
*
*     .. Parameters ..
      DOUBLE PRECISION   ZERO, ONE
      PARAMETER          ( ZERO = 0.0D+0, ONE = 1.0D+0 )
*     ..
*     .. Local Scalars ..
      INTEGER            I, INFO, J, K, L
      DOUBLE PRECISION   ANORM, BNORM, RESID, TEMP, ULP, ULPINV, UNFL
*     ..
*     .. External Functions ..
      DOUBLE PRECISION   DLAMCH, DLANGE, DLANSY
      EXTERNAL           DLAMCH, DLANGE, DLANSY
*     ..
*     .. External Subroutines ..
      EXTERNAL           DCOPY, DGEMM, DGGSVD, DLACPY, DLASET, DSYRK
*     ..
*     .. Intrinsic Functions ..
      INTRINSIC          DBLE, MAX, MIN
*     ..
*     .. Executable Statements ..
*
      ULP = DLAMCH( 'Precision' )
      ULPINV = ONE / ULP
      UNFL = DLAMCH( 'Safe minimum' )
*
*     Copy the matrix A to the array AF.
*
      CALL DLACPY( 'Full', M, N, A, LDA, AF, LDA )
      CALL DLACPY( 'Full', P, N, B, LDB, BF, LDB )
*
      ANORM = MAX( DLANGE( '1', M, N, A, LDA, RWORK ), UNFL )
      BNORM = MAX( DLANGE( '1', P, N, B, LDB, RWORK ), UNFL )
*
*     Factorize the matrices A and B in the arrays AF and BF.
*
      CALL DGGSVD( 'U', 'V', 'Q', M, N, P, K, L, AF, LDA, BF, LDB,
     $             ALPHA, BETA, U, LDU, V, LDV, Q, LDQ, WORK, IWORK,
     $             INFO )
*
*     Copy R
*
      DO 20 I = 1, MIN( K+L, M )
         DO 10 J = I, K + L
            R( I, J ) = AF( I, N-K-L+J )
   10    CONTINUE
   20 CONTINUE
*
      IF( M-K-L.LT.0 ) THEN
         DO 40 I = M + 1, K + L
            DO 30 J = I, K + L
               R( I, J ) = BF( I-K, N-K-L+J )
   30       CONTINUE
   40    CONTINUE
      END IF
*
*     Compute A:= U'*A*Q - D1*R
*
      CALL DGEMM( 'No transpose', 'No transpose', M, N, N, ONE, A, LDA,
     $            Q, LDQ, ZERO, WORK, LDA )
*
      CALL DGEMM( 'Transpose', 'No transpose', M, N, M, ONE, U, LDU,
     $            WORK, LDA, ZERO, A, LDA )
*
      DO 60 I = 1, K
         DO 50 J = I, K + L
            A( I, N-K-L+J ) = A( I, N-K-L+J ) - R( I, J )
   50    CONTINUE
   60 CONTINUE
*
      DO 80 I = K + 1, MIN( K+L, M )
         DO 70 J = I, K + L
            A( I, N-K-L+J ) = A( I, N-K-L+J ) - ALPHA( I )*R( I, J )
   70    CONTINUE
   80 CONTINUE
*
*     Compute norm( U'*A*Q - D1*R ) / ( MAX(1,M,N)*norm(A)*ULP ) .
*
      RESID = DLANGE( '1', M, N, A, LDA, RWORK )
*
      IF( ANORM.GT.ZERO ) THEN
         RESULT( 1 ) = ( ( RESID / DBLE( MAX( 1, M, N ) ) ) / ANORM ) /
     $                 ULP
      ELSE
         RESULT( 1 ) = ZERO
      END IF
*
*     Compute B := V'*B*Q - D2*R
*
      CALL DGEMM( 'No transpose', 'No transpose', P, N, N, ONE, B, LDB,
     $            Q, LDQ, ZERO, WORK, LDB )
*
      CALL DGEMM( 'Transpose', 'No transpose', P, N, P, ONE, V, LDV,
     $            WORK, LDB, ZERO, B, LDB )
*
      DO 100 I = 1, L
         DO 90 J = I, L
            B( I, N-L+J ) = B( I, N-L+J ) - BETA( K+I )*R( K+I, K+J )
   90    CONTINUE
  100 CONTINUE
*
*     Compute norm( V'*B*Q - D2*R ) / ( MAX(P,N)*norm(B)*ULP ) .
*
      RESID = DLANGE( '1', P, N, B, LDB, RWORK )
      IF( BNORM.GT.ZERO ) THEN
         RESULT( 2 ) = ( ( RESID / DBLE( MAX( 1, P, N ) ) ) / BNORM ) /
     $                 ULP
      ELSE
         RESULT( 2 ) = ZERO
      END IF
*
*     Compute I - U'*U
*
      CALL DLASET( 'Full', M, M, ZERO, ONE, WORK, LDQ )
      CALL DSYRK( 'Upper', 'Transpose', M, M, -ONE, U, LDU, ONE, WORK,
     $            LDU )
*
*     Compute norm( I - U'*U ) / ( M * ULP ) .
*
      RESID = DLANSY( '1', 'Upper', M, WORK, LDU, RWORK )
      RESULT( 3 ) = ( RESID / DBLE( MAX( 1, M ) ) ) / ULP
*
*     Compute I - V'*V
*
      CALL DLASET( 'Full', P, P, ZERO, ONE, WORK, LDV )
      CALL DSYRK( 'Upper', 'Transpose', P, P, -ONE, V, LDV, ONE, WORK,
     $            LDV )
*
*     Compute norm( I - V'*V ) / ( P * ULP ) .
*
      RESID = DLANSY( '1', 'Upper', P, WORK, LDV, RWORK )
      RESULT( 4 ) = ( RESID / DBLE( MAX( 1, P ) ) ) / ULP
*
*     Compute I - Q'*Q
*
      CALL DLASET( 'Full', N, N, ZERO, ONE, WORK, LDQ )
      CALL DSYRK( 'Upper', 'Transpose', N, N, -ONE, Q, LDQ, ONE, WORK,
     $            LDQ )
*
*     Compute norm( I - Q'*Q ) / ( N * ULP ) .
*
      RESID = DLANSY( '1', 'Upper', N, WORK, LDQ, RWORK )
      RESULT( 5 ) = ( RESID / DBLE( MAX( 1, N ) ) ) / ULP
*
*     Check sorting
*
      CALL DCOPY( N, ALPHA, 1, WORK, 1 )
      DO 110 I = K + 1, MIN( K+L, M )
         J = IWORK( I )
         IF( I.NE.J ) THEN
            TEMP = WORK( I )
            WORK( I ) = WORK( J )
            WORK( J ) = TEMP
         END IF
  110 CONTINUE
*
      RESULT( 6 ) = ZERO
      DO 120 I = K + 1, MIN( K+L, M ) - 1
         IF( WORK( I ).LT.WORK( I+1 ) )
     $      RESULT( 6 ) = ULPINV
  120 CONTINUE
*
      RETURN
*
*     End of DGSVTS
*
      END